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Could people breathe on Mars? – Jack J., 7, Alexandria, Virginia
Suppose you are an astronaut who has just landed on the planet Mars. What would you need to survive?
To start, here is a short list: Water, food, shelter – and oxygen.
Oxygen is in the air we breathe here on Earth. Plants and certain types of bacteria provide it to us.
But oxygen is not the only gas present in the Earth’s atmosphere. It’s not even the most abundant. In fact, only 21% of our air is made up of oxygen. Almost all the rest is nitrogen – around 78%.
Now you might be wondering: if there is more nitrogen in the air, why are we breathing oxygen?
Here’s how it works: Technically, when you inhale, you absorb everything in the atmosphere. But your body only uses oxygen; you get rid of the rest when you exhale.
Air on Mars
The Martian atmosphere is thin – its volume is only 1% of Earth’s atmosphere. In other words, there is 99% less air on Mars than on Earth.
That’s partly because Mars is about half the size of Earth. Its gravity is not strong enough to prevent atmospheric gases from escaping into space.
And the most abundant gas in this thin air is carbon dioxide. For people on Earth, it is a poisonous gas in high concentration. Fortunately, it makes up far less than 1% of our atmosphere. But on Mars, carbon dioxide represents 96% of the air!
Meanwhile, Mars has almost no oxygen; it’s only a tenth of one percent of the air, not enough for humans to survive.
If you tried to breathe on the surface of Mars without a spacesuit supplying your oxygen – bad idea – you would die in an instant. You would suffocate, and because of the low atmospheric pressure, your blood would boil, both at about the same time.
life without oxygen
So far, researchers have found no evidence of life on Mars. But the research has only just begun; our robotic probes barely scratched the surface.
Without a doubt, Mars is an extreme environment. And it’s not just looks. There is very little liquid water on the surface of Mars. The temperatures are incredibly cold – at night it is over -100 degrees Fahrenheit (-73 degrees Celsius).
But many organisms on Earth survive extreme environments. Life has been discovered in the ice of Antarctica, at the bottom of the ocean and miles below the Earth’s surface. Many of these places have extremely hot or cold temperatures, almost no water, and little or no oxygen.
And even if life no longer exists on Mars, perhaps it did billions of years ago, when it had a thicker atmosphere, more oxygen, warmer temperatures, and significant amounts liquid water on the surface.
That’s one of the goals of NASA’s Mars Perseverance rover mission – to search for signs of ancient Martian life. That’s why Perseverance searches Martian rocks for fossils of organisms that once lived – most likely, primitive life, like Martian microbes.
Do-it-yourself oxygen
Among the seven instruments aboard the Perseverance rover is MOXIE, an incredible device that extracts carbon dioxide from the Martian atmosphere and turns it into oxygen.
If MOXIE works as scientists hope, future astronauts won’t just make their own oxygen; they could use it as a component in the rocket fuel they will need to get back to Earth. The more oxygen people are able to make on Mars, the less they’ll need to bring from Earth – and the easier it becomes for visitors to get there. But even with “homemade” oxygen, astronauts will still need a spacesuit.
Right now, NASA is working on the new technologies needed to send humans to Mars. That could happen within the next decade, possibly in the late 2030s. By then, you’ll be an adult – and perhaps one of the first to step onto Mars.
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This article is republished from The Conversation under a Creative Commons license. Read the original article here: https://theconversation.com/could-people-breathe-the-air-on-mars-180504.
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